Chassis lubrication systems

ABSTRACT

A motion transfer device is provided for use in lubricating apparatus and systems. This device is for axial mounting on a pump having a rotating shaft. A diaphragm 17 is moved by reduced air pressure in space 16 and moves an inner housing 23 axially. Housing 23 cooperates with member 19 via balls 21 running in helical grooves in the housing and member. This member causes shaft 1 to rotate by use of a pawl and ratchet (14,15). Housing 23 is constrained to move axially by balls 24 rolling in axial grooves in the housing 23 and on part 29 (FIG. 1).

Unlted States Patent 1151 3,667,574

Grantham 45 Ju 6, 1972 [541 CHASSIS LUBRICATION SYSTEMS 2,942,580 6/1960Siravo ..74/89l 3,075,395 l/l963 Leland.. ..74/89 [72] Invent 2 g:mympmn' 3,308,410 3/1967 Biser ...74/88 x 3,456,761 7/1969 W001 et a1..1s4/7 [73] Assignee: Tecalemit (Engineering) Limited,

Plymouth, Devon England Primary Examiner-Manuel A. Antonakas 2 lAttorneyMason, Kolehmainen, Rathbum & Wyss [2 Fi ed: Dec. 2, 1969 21Appl. No.2 881,423 [57] ABSHMCT A motion transfer device is provided foruse in lubricating apparatus and systems. This device is for axialmounting on a [30] Fore'gn Applicatmn Pnomy Data pump having a rotatingshaft. A diaphragm 17 is moved by Dec. 3, 1968 Great Britain ..57,369/68reduced Pressure in space 16 an musing 23 axially. Housing 23 cooperatesw1th member 19 v1a balls 21 running in helical grooves in the housingand member. This (gill. g, member causes Shaft 1 to rotate by use of apawl and ratchet 58 d n (14,15). Housing 23 is constrained to moveaxially by balls 24 1 o arc "184/71 74/89 89 88 rolling in axial groovesin the housing 23 and on part 29 (FIG.

1). [56] References Cited 3 Claims, 2 Drawing Figures UNITED STATESPATENTS A 2,978,915 4/1961 Metcalf .74/89 I I r I3 ,4 }/4 234 i A 3A 43A 3 25 PATENTED H 6 9 2 3, 667.- 574 SHEET 1 BF 2 crmssrs LUBRICATIONSYSTEMS This invention provides a modification to the lubricatingapparatus described and claimed in U.S. Pat. No. 3,456,761.

The lubricating apparatus is operated by air under reduced or increasedpressure and for use under reduced pressure a large diameter/strokeratio is required. In order to obtain a compact arrangement, the deviceoperated by the reduced pressure should be mounted axially on the pump.The present invention provides a motion transfer device, operable underreduced or increased air pressure, which is axially mounted on thelubricant pump.

The motion transfer device of the invention provides a generallycylindrical first housing, which is axially reciprocable by pressurebelow or above atmospheric pressure, and reciprocably rotates anotherhousing (which is preferably within the first housing) through at leasttwo balls between and contacting the housing and cooperating with ahelical trough in one of them.

A low torque action can be achieved by positioning parallel andcorresponding helical troughs on opposed surfaces of the first housingand the other housing. The balls are restrained to transfer motionbetween the housings by being positioned in a slot in a member betweenthe housings. Preferably this slot is helically positioned on the memberand is also normal to the troughs on the housings. I The first housingmay be restrained to move axially, by having balls moving in cooperatingaxial troughs on opposed faces of the first housing and a fixed housing,which will preferably be external to the first housing.

An embodiment of the motion transfer device according to the inventionwill now be described by way of example with reference to theaccompanying diagrammatic drawings in which:

FIG. 1 shows a longitudinal section through the device and theassociated pump mechanism; and

- FIG. 2 shows a radial section through the device along the crankedline IIII of FIG. 1.

A shaft 1 extends along the cylindrical axis of a pump housing 2. Theshaft is carried in a bush 7 in an end wall 8 of the housing and in anannular bearing 10 in an opposed end wall 9. Pumps 3 extend through thehousing 2 and open into a pump space 5 within the housing, the pumpshave pistonends 3A which are movableradially by cams 4. These cams arekeyed to the shaft 1 so that rotation of the shaft causes the pistonends 3A to reciprocate thus operating the pumps 3 and moving lubricantfrom the pump space 5, through the pumps, to a lubricant supply system.Lubricant enters into the space 5 through inlet 6.

It will be noted that the movement necessary to work the pumps isprovided by rotation of shaft 1 and on the right handside of FIG. 1 isseen the device which provides a transfer of motion from a reciprocatinglinear type to a stepwise angular type. It is to this device that thisinvention is particularly directed as a modification of the apparatusdescribed and claimed in U.S. Pat. No. 3,456,761.

A cylindrical housing part 11 and an end housing part 12 are attached tothe outer face of end wall 9 by means of peripheral bolts. A fluid inlet13 is in the housing part 12 and through this inlet 13 can be suppliedoperating fluid at a pressure above or below atmospheric pressure. Theembodiment to be described is operated by pulses of reduced pressure butthe invention contemplates a device operated by increased pressure. Theoperating fluid is obtained as proposed in U.S. Pat. No. 3,456,761. Theinlet 13 communicates with a pressure space 16 existing between the endhousing part 12 and a flexible diaphragm 17 peripherally clamped betweenthe housing parts 11, 12. The diaphragm 17 is biassed from the part 12by a helical spring 18 within the space 16. This diaphragm is shown inits rest position so that reduction of pressure in space 16 moves thediaphragm outwardly towards the housing part 12 compressing the spring18.

It is convenient to consider now the components of the device adjacentthe shaft 1, which are moved by the diaphragm under operatingconditions. A ratchet wheel 14 having peripheral ratchet teeth isattached to the shaft 1. The teeth cooperate with a pawl 15 carried onan inner member 19 which embraces the wheel 14 and is joumalled onshaft 1. Thus angular reciprocation of member 19 causes stepwiserotation, in one direction, of the wheel 14 and hence the shaft 1, i.e.unidirectional clutch means are provided between the other housing andthe shaft.

The pawl and ratchet cooperation can be clearly seen in FIG. 2. The pawlis biased against the teeth so that it rides over the wheel when themember 19 rotates in one direction (anticlockwise in FIG. 2). On theexternal cylindrical surface of the member 19 there are three troughlike ball tracks 20. These tracks are at an angle of approximately 45 tothe cylindrical longitudinal axis of the member 19. The tracks 20 areangularly spaced around member 19 (see FIG. 2) and it is possible toutilize more tracks although a pair of tracks is considered the minimum.Balls 21 are positioned in the tracks 20 being movable along thesetracks and corresponding tracks 23A, parallel to tracks 20, on the innersurface of the cylindrical part of a cup-shaped inner housing 23. Theballs also lie in slots in a cylindrical keeper ring 22 attached to theend wall 9. These slots are helically positioned in the ring 22 and areeach normal to the pairs of tracks 20 and 23A. If the inner housing 23is reciprocated thus axially (i.e. towards and away from the shaft 1)the balls 21 roll in their tracks 20, 23A and a'rotational force istransmitted to the member 19 through the track 20 also, being restrainedby the ring 22 the balls 21 are held in position during the period inwhich reversal of direction of motion takes place.

An axial movement is given to the housing 23 because it is attached tothe diaphragm 17 with the aid of a bolt extending through the diaphragmand a diaphragm plate on the outer surface of the diaphragm. However itis necessary to constrain the housing 23 to move in an axial pathbecause if this was not ensured, the housing would rotate as the ballsmoved along tracks 23A in a sliding manner.

The rotational force may also be transferred to the member 19 by a ballmovable in an axial trough in housing 23 and in a helical trough invmember 19. Alternatively the member 19 may carry the axial trough andthe housing 23 the helical trough. However, the embodiment specificallydescribed in which a ball rolls in parallel corresponding helicaltroughs, allows a pure rolling action of the ball to be obtained becausethe path lengths in the troughs are the same. The alternatives proposeduse paths of unequal length so that some sliding of the ball will occur.The pure rolling action gives a lower torque to the system. I

The housing 23 is constrained to move in an axial reciprocating path byballs 24which roll in axial troughs 25, 26. Troughs 25 are on theexternal surface of housing 23 and troughs 26 on the internal surface ofa fixed housing 29 attached to end wall 9. The system of axial troughsand balls (of which there are three) causes the housing to follow anaxial reciprocating path although it is subjected to a reaction rotationforce from the helical trough system.

Other means may be used to constrain the housing 23, for example anextension from housing 23 or housing 29 moving in an axial trough in theother housing. However, the use of rolling balls reduces the frictionalloss.

The balls 24 are retained in their pairs of troughs by a ball retainingring 27 biased from a radially outwardly directed flange on the housing23 by a helical return spring 28.

When air below atmospheric pressure is introduced into the pressurespace 16 the diaphragm 17 moves outwardly and thus moves housing 23 fromend wall 9. This housing 23 moves clockwise (seen as in FIG. 2) and thewheel 14 follows this rotation due to cooperation with pawl 15. Releaseof pressure allows the housing to move anticlockwise due to the returnforce of spring 18. The pawl rides over the ratchet teeth with the wheel14 not rotating.

It will be appreciated that the motion transfer device can be used incombination with a lubricant pump to perform the invention as claimed inthe main patent without necessarily rotating a shaft actuating separatepumps. Thus the pump may have other forms in which a rotary motioncauses movement of a pump operating member, for example a piston. Thusthe present invention provides a motion transfer device which allows alubricant pump to be operated by pulses of air of increased or reducedpressure. The device of the invention can be made in a compact form.

I claim:

1. In a lubricating apparatus for a vehicle comprising a pump operatedby a shaft rotated by air pressure acting on a member, the improvementincluding a motion transfer device comprising a member movable axiallyrelative to a shaft by air pressure and fixed to a first housing, asecond housing coaxial with the first and reciprocably rotatable aboutthe shaft axis by axial movement of said first housing, said twohousings being arranged one with the other so that a cylindrical insidesurface of one housing surrounds a cylindrical outer surface of theother housing, a fixed keeper mounted between said two adjacentcylindrical surfaces and including a pair of helical slots definedtherein, at least two balls disposed between said adjacent cylindricalsurfaces of said two housings, each ball mounted within a helical slotin said fixed keeper and movable in a helical trough defined in saidcylindrical surface of said first housing and a cooperating paralleltrough in said cylindrical surface of the second housing, each slotbeing arranged at an angle to said troughs and unidirectional clutchmeans between said housings.

2. A device as claimed in claim I, in which said troughs are aligned onan angle of approximately 45 relative to the longitudinal axis of saidshaft.

3. A device as claimed in claim 2, in which said helical slots in saidkeeper are normal to the troughs fonned in said housmgs.

1. In a lubricating apparatus for a vehicle comprising a pump operatedby a shaft rotated by air pressure acting on a member, the improvementincluding a motion transfer device comprising a member movable axiallyrelative to a shaft by air pressure and fixed to a first housing, asecond housing coaxial with the first and reciprocably rotatable aboutthe shaft axis by axial movement of said first housing, said twohousings being arranged one with the other so that a cylindrical insidesurface of one housing surrounds a cylindrical outer surface of theother housing, a fixed keeper mounted between said two adjacentcylindrical surfaces and including a pair of helical slots definedtherein, at least two balls disposed between said adjacent cylindricalsurfaces of said two housings, each ball mounted within a helical slotin said fixed keeper and movable in a helical trough defined in saidcylindrical surface of said first housing and a cooperating paralleltrough in said cylindrical surface of the second housing, each slotbeing arranged at an angle to said troughs and unidirectional clutchmeans between said housings.
 2. A device as claimed in claim 1, in whichsaid troughs are aligned on an angle of approximately 45* relative tothe longitudinal axis of said shaft.
 3. A device as claimed in claim 2,in which said helical slots in said keeper are normal to the troughsformed in said housings.